The 4th Workshop on Nano Security will be held at the Design Automation and Test in Europe Conference on April 21 in Verona, Italy. The workshop has an attractive program that includes a keynote by Professor Massimo Alioto on Intelligent & Perceptive Attack Counteraction for Next-Generation Secure Chips; a special session on secure compute-in-memory architectures; three technical sessions on modeling and simulation; physical attack protections; and emerging technologies; and a poster session on the projects from the DFG Priority Program SPP 2253 Nano Security.